Electrical connector



Dec. 1s, 1970 W,TEAGNO [my 3,548,368

ELECTRICAL CONNECTOR 2 Y.Sheets-sheet 1 Filed Feb. 24, 1969 WEA/70H Wladimiro Teogno Nerino Iskra @f da@ auf@ Dec. 15., 1970 w, TEAGNQ ETAL 3,548,368

n ELECTRICAL CONNECTOR Filed Feb. 24,' 1969 2 sheets-sheet 2 FIG] Wladimiro Teagno Nerino .Iskra United States Patent O 3,548,368 ELECTRICAL CONNECTOR Wladimiro Teagno and Nerino Iskra, Turin, Italy, as-

signors, by mesne assignments, to AMP Incorporated,

Harrisburg, Pa.

Filed Feb. 24, 1969, Ser. No. 801,587 Claimspriority, application Italy, Nov. 2, 1968, 828,154 Int. Cl. H01r 11/22 U.S. Cl. 339-252 8 Claims ABSTRACT OF THE DISCLOSURE An ignition connector has a socket portion provided with a circumferential rim near a crimping ferrule and a longitudinal rib merging with the circumferential rib and being aligned with a neck connecting the socket portion and ferrule to improve resistance to lateral tension on the ignition cable when crimped in the ferrule.

This invention relates to an electrical connector for making releasable electrical connection with either a spark plug stem or an ignition voltage distributor receptacle. Such connectors usually comprise a generally tubular contact portion having at one end a connecting portion, for example, a crimping ferrule, for connection to an electrical lead, the contact portion and the connecting portion being joined by a neck which extends from an edge of the contact portion. The contact portion is arranged to receive a spark plug stem to make good electrically-conductive contact with the stem and can also be inserted into the distributor receptacle to engage the internal surface of the distributor receptacle to make good electrically-conductive contact with the receptacle. The contact portion may engage the internal surface of the receptacle through ribs formed in and projecting outwardly of the contact portion.

According to the invention, an electrical connector for making releasable electrical connection with either a spark plug stem or an ignition voltage distributor receptacle comprises a generally tubular contact portion to one end of which a connecting portion for connection to an electrical lead is joined by a neck which extends from an edge of the contact portion, the contact portion having a radially outwardly-projecting circumferentially-extending rib and a radially outwardly-projecting longitudinal rib for engaging the internal surface of the distributor receptacle, the circumferentially-extending rib being disposed near that end of the contact portion from which the neck extends and the longitudinal ri'b being axially aligned with the neck and merging with the circumferentially-extending rib.

It is an object of the invention that where, as a result o'f the lead being strained transversely of the longitudinal axis of the spark plug stem (when the connecting portion is mated with the stem) as a result of the lead being pulled or shaken, the presence of the circumferential rib in the vicinity of the junction between the contact portion and the neck and the fact that the longitudinally-extending rib merges with the circumferential rib, improve the reinforcement of the contact portion against the straining of the lead.

Another object is that the contact portion preferably has further radially outwardly-projecting longitudinal ribs, which also merge with the circumferentially-extending rib, the longitudinal ribs, which are evenly distributed 3,548,368 Patented Dec. l5, 1970 ICC about the circumference o'f the contact portion, co-operating to guide the contact portion into the distributor receptacle and to stabilize the contact portion in the receptacle. A further object is that the circumferentiallyextending rib can conveniently engage in a peripheral recess near the mouth of the receptacle. An additional object is that at least one of the longitudinal ribs may have a projection which also engages in the recess to cornpensate for oversize of the recess with respect to the circumferentially-extending rib. A still further object is that the contact portion may have radially inwardly-extending pimples formed in the longitudinally-extending edge portions of a sheet metal blank from which the connector has been rolled, the pimples being generally triangular as seen in plan view, with the bases of the triangles coinciding with the edges of the blank, the pimples being disposed opposite to one another.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there are shown and described illustrative embodiments of the invention; it is to be understood, however, that these embodiments are not intended to be exhaustive nor limiting of the invention but are given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as rnay be best suited to the conditions of a particular use.

For a better understanding of the invention, reference will now be made by way of example to the accompanying drawings, in which:

FIG. 1 is a top plan view of an electrical connector for making releasable electrical connection either with a spark plug stem or an ignition voltage distributor receptacle;

FIG. 2 is a side elevational view of the connector;

FIG, 3 is an enlarged cross-sectional view taken on the line 3 3 of FIG. l;

FIG. 4 is an enlarged cross-sectional view taken on the line 4 4 of FIG. 1;

FIG. 5 is an elevational view partly in section showing the connector crimped to a cable and mated with an ignition voltage distributor receptacle;

FIG. 6 is an elevational view of the connector crimped to a cable end and mated with a spark plug stem which is shown in broken lines.

FIG. 7 is an enlarged side elevational view of a modied form of the connector crimped to a cable; and

FIG. 8 is atop plan View of FIG. 7.

Reference will now be made to FIGS. 1 to 4. The connector, which has been made by rolling a blank of spring sheet metal, comprises a connecting portion 2 and a contact portion 4. The portion 2 is formed by an essentially U-section crimping ferrule having upstanding side walls or legs 6 extending from opposite sides of a web 8 having an inwardly-projecting rib 10 which extends into the side walls 6. A series of lances 12 produced by perforating the base 8 project inwardly of the portion 2. The portion 2 is joined to the portion 4 by a neck 14 of the connector material. The portion 4 is generally tubular, having at its end nearest the portion 2 a circumferentially-extending rib 16 which extends about substantially the Whole periphery of the portion 4 and which projects radially outwardly of the portion 4. A first longitudinal radially outwardly-projecting rib 18 of the portion 4 is disposed on the opposite side of the longitudinally extending edges 20 of the blank from which the connector was produced, and it merges with the rib 16 at 22. The portion 4 has second and third longitudinal radially outwardly-projecting ribs 24 and 26. These ribs, however, do not merge with the rib 16. The ribs 18, 24 and 26 are evenly distributed about the periphery of the portion 4 as best seen in FIG. 3. Radially inwardly-projecting and oppositely-disposed pimples 28 are formed in the vicinity of the edges 20 by bending the material of the portion 4 inwardly, and they are generally triangular as seen in FIG. 1, with the bases of the triangles coinciding with the edges 20. The pimples 28 are disposed approximately midJway between the rib 16 and the left-hand (as seen in FIGS. 1 and 2) end of the portion 4. A further pimple 29 projects radially outwardly from the rib 18 in the vicinity of its junction with the rib 16.

As seen in FIGS. 5 and 6, the portion 2 has been crimped about an end of a high voltage insulated ignition cable 30. Prior to the crimping operation, the end of the electrically conductive central core 32 of the cable was bared and bent back to lie alongside the cable end. As a result of the crimping operation, the rib presses the core 32 against the cable 30 to make good electrically conductive connection between the core 32 and the connector, the rib 10 also serving to restrain relative axial movement between the connector and the cable. Also, as a result of the crimping operation, the lances 12 are driven into the insulation of the cable further to restrain the relative axial movement.

As seen in FIG. 5, which shows the connector mated with a high voltage distributor receptacle R, the rib 16 engages in the upper (as seen in FIG. 5) part of a circumferential internal recess RC in the receptacle R (the recess RC being considerably oversized with respect to the rib 16), the pimple 29 engaging in the lower (as seen in FIG. 5 part of the recess RC. Where the recess RC is not so oversized the pimple 29 is compressed and flattened by the wall of the recess RC. The ribs 16, 18, 24 and 26 serve to guide and center the contact portion 4 with respect to the receptacle, during its insertion into the receptacle, and engage the receptacle wall in the mated condition ofthe connector and receptacle, as shown in FIG. 5. These ribs also enhance the spring characteristics of the contact portion.

Since the leading end of the contact portion 4 has no peripheral rib or other projection to engage in the recess RC during the insertion of the portion 4 into the receptacle R, full insertion of the contact portion will be correctly indicated by a click as the rib 16 snaps into the recess RC.

As seen in FIG. 6, which shows the connector mated with a spark plug stem S having a head H, the pimples 28 engage beneath the head H to restrain withdrawal of the connector from the stem S. The pimples 28 may be axially displaced with respect to one another to allow for tolerance variations. The rib 16 serves to stilen the contact portion 4 in the vicinity of the neck 14 against forces applied to the contact portion 4 by way of the neck 14 if the cable 30 is strained transversely of the longitudinal axis of the stern S. This stifening is augmented by the fact that the rib 18 merges with the rib 16 in the vicinity of the neck 14 and lies in axial alignment with the neck 14.

The pimple 29 is positioned along the rib 18 in accordance with the width and position of the recess RC, which may vary from one make of distributor receptacle to another.

It is not essential for elective connection between the distributor receptacle and the connector that the rib 16 should engage in the internal recess of the distributor receptacle.

Instead of the rib 10, the connecting portion 2 may be provided with a struck-out lance (not shown) for piercing 4 the insulation of the cable to make electrically conductive contact with the cable core.

The leading edge of the Contact portion 4 may be chamfered to facilitate insertion of the portion 4 into the distributor receptacle and the leading corners of the edges 20 may be rounded off to facilitate mating the portion 4 with the spark plug stern.

Reference will now be made to FIGS. 7 and 8. The connector, which has been made by rolling a blank of spring sheet metal, comprises a connecting portion 2a and an essentially tubular contact portion 4a joined to the portion 2a by a neck 14a. The portion 2a, which was originally of essentially U-section in the manner of the connecting portion 2 described above with reference to FIGS. 1 to 4, has been crimped about an end of a high voltage insulated ignition cable 30a so that an essentially triangular-shaped lance (not shown) but struck out from opening 33 in leg 6a and extending from the base of the connecting portion 42a pierced the insulation of the cable 30a to make electrically conductive contact with the electrically conductive core (not shown) of the cable 30a. A lance from each leg 6a may be provided. The portion 4a has at its end nearest the portion 2a a circumferentially-extending rib 16a which projects radially outwardly of the portion 4a. Three radially outwardly projecting longitudinal ribs 18a, 24a and 26a are evenly spaced from one another about the periphery of the portion 4a and each merge with the circumferentially-extending rib 16a. The rib 18a is in axial alignment with the neck 14a. The portion 4a has pimples 28a similar to the pimples 28 described above with reference to FIGS. 1 to 6 and serving the same purpose as the pimples 28. The connecting portion 4a may also be provided, if desired, with a pimple (not shown) corresponding to the pimple 29 of FIGS. l to 6.

The fact that all the longitudinal ribs 18a, 24a and 26a merge with the rib 16a serves to reinforce the portion 4a against the cable 30a being pulled transversely of the longitudinal axis of the connector when the connector is mated with the spark plug stem.

-It Will, therefore, be appreciated that the aforementioned and other desirable objects have been achieved; however, it -should be emphasized that the particular embodiments of the invention, which are shown and described herein, are intended as merely illustrative and not as restrictive of the invention.

The invention is claimed in accordance with the following:

l. An electrical connector for making releasable electrical connection with either a spark plug stem or an ignition voltage distributor receptacle, the connector comprising a generally tubular contact portion, a connecting portion for connection to an electrical lead, a neck extending from an edge of the contact portion and connecting said contact portion and said connecting portion together, the contact portion having a radially outwardlyprojecting circumferentially-extending rib and a radially outwardly-projecting longitudinal rib for engaging the internal surface of the distributor receptacle, the circumferentialy-extending rib being disposed near that end of the contact portion from which the neck extends, the longitudinal rib being axially aligned with the neck and merging with the circumferentially-extending rib.

2. A connector according to claim 1, in which the longitudinally-extending rib has a radially outwardlyextending projection in the vicinity of its junction with the circumferentially-extending rib.

3. A connector according to claim 1, in which the contact portion has further radially outwardly-projecting longitudinal ribs which also merge with the circumferentially-extending rib, the longitudinally-extending ribs being evenly distributed circumferentially of the contact portion.

4. A connector according to claim 1, in which additional longitudinal ribs project outwardly from said contact portion with the longitudinal ribs being evenly distributed circumferentially around the contact portion.

5. A connector according to claim 1, in which the contact portion has, substantially mid-way between the circumferentially-extending rib and the other end of the contact portion, radially inwardly-projecting pimples at edges of a sheet metal blank from which the connector has been rolled.

6. A connector according to claim 5, in which the pimples are disposed opposite each other.

7. A connector according to claim 5, in which the pimples are generally triangular as seen in plan view Y With the bases of the triangles being coincident with the edges of the blank.

8. An electrical connector comprising a contact portion of generally tubular conguration and having edges disposed opposite one another, a ferrule portion, a neck portion extending between said contact portion and Isaid ferrule portion and connecting these portions together,

a circumferential rib adjacent an inner end of said contact portion, and a longitudinal rib extending along said contact portion in alignment with said neck portion and merging with said circumferential rib.

References Cited UNITED STATES PATENTS 3,243,763 3/1966 Elliott 339-223 3,423,718 1/1969 Cea 339--100 FOREIGN PATENTS 1,514,956 l/1968 'France 339--97C MARVIN A. CHAMPION, Primary Examiner I. H. MCGLYNN, Assistant Examiner U.S. Cl. X.R. 339--258 

